Conventionally, when mounting electronic components on a glass substrate or suchlike, an anisotropic conductive film (hereinafter, referred to as an “ACF”) is used in some cases. The ACF is often in the form of a sheet or tape, and used as an anisotropic conductive adhesive on a resin sheet or tape called a “separator (or base film)”. The anisotropic conductive adhesive is normally used by removing only the separator after thermocompression bonding of the ACF onto a substrate surface (such transfer bonding is referred to as “lamination”). In this manner, the ACF is normally affixed to an entire substrate surface, but it might be affixed for each electronic component (see, for example, Japanese Laid-Open Patent Publication No. 2004-6793). An example of this will be described below with reference to FIG. 8.
FIG. 8 is a schematic top view of a conventional liquid crystal module 600 to be provided in a cell phone or suchlike. As shown in FIG. 8, the liquid crystal module 600 includes two opposingly arranged glass substrates 610 and 615, an LSI chip 630, an FPC board 640, and a plurality of discrete electronic components 650 such as capacitors. Herein, the “liquid crystal module” will refer below to a board module including two opposingly arranged glass substrates, as well as an LSI chip, an FPC board, and electronic components, such as capacitors, mounted on any of the glass substrates, but not including any backlight or polarizing plate.
In a space between the two glass substrates 610 and 615, a display portion 620 is formed with a liquid crystal (not shown) enclosed with a seal material (not shown). The glass substrate 610 has a projection 611 on which are mounted the large-scale integration (hereinafter, referred to as “LSI”) chip 630 having a driver function required for driving the display portion 620, the flexible printed circuit (hereinafter, referred to as “FPC”) board 640 connected to external electronic equipment, and the discrete electronic components 650, such as capacitors, which are required for operating the LSI chip 630. When a video signal, a control signal, and a source voltage are externally provided to the LSI chip 630 via the FPC board 640, the display portion 620 displays video.
The LSI chip 630 and the FPC board 640 are mounted on the projection 611 using a chip ACF 630a and an FPC ACF 640a, respectively. Moreover, the discrete electronic components 650 are mounted on the projection 611 using component ACFs 650a to be affixed to their respective groups of discrete electronic components 650 adjacent to one another. In this manner, a plurality of component ACFs 650a are required for mounting the discrete electronic components 650 on the projection 611. The component ACFs 650a are affixed to the projection 611 one after another, and therefore, upon affixation of the component ACFs 650a, in some cases, the component ACFs 650a affixed adjacently might contact each other, or the component ACFs 650a might contact the LSI chip 630 and the FPC board 640 which are mounted in advance, so that the affixed component ACFs 650a deviate from their desired positions.
To prevent occurrence of such deviation, it is necessary to ensure sufficient space between affixing positions of adjacent component ACFs 650a. However, ensuring sufficient space between affixing positions of adjacent component ACFs 650a results in an increased area of the projection 611, making it difficult to achieve a reduced frame area of the liquid crystal module 600.
Therefore, focusing attention on the fact that the chip ACFs 630a and the component ACFs 650a can be provided in common, a large sheet of ACF including them is affixed to the projection and used to mount an LSI chip and a plurality of discrete electronic components on the projection, and an FPC board is mounted on the projection further using an FPC ACF 640a on the ACF sheet (see, for example, Japanese Laid-Open Patent Publication No. 2006-235295).